Lead and arsenic free, and preferably gadolinium and further preferably also fluorine free, optical glasses for the application fields mapping, projection, telecommunication, optical communication engineering, mobile drive, laser technology and/or micro lens arrays have a refractive index of 1.91≦nd≦2.05, an Abbe number of 19≦νd≦25 and have a low transformation temperature, namely of less than or equal to 470° C. and preferably of less than or equal to 450° C., as well as good producability and processability and crystallization stability.